If you installed Forefront TMG on a computer running Windows Server 2008, and you want to upgrade the operating system to Windows Server 2008 R2, you must perform a clean installation of Windows Server 2008 R2. The supported upgrade path is:

Export the Forefront TMG configuration.

Perform a clean installation (not an upgrade) of the new operating system.

If you are running the Performance Tool or Setup from a shared drive, make sure that the computer automatically reconnects to this drive after system restart. These two applications may require or initiate a restart, and failure to locate them after restart may result in a failed installation.

When installing Forefront TMG on a computer that is joined to a domain with Group Policy object (GPO) enforcement of Windows Firewall, the installation will not complete successfully because Setup tries to disable the Windows Firewall. As a workaround, you can direct Setup to ignore this error by adding a flag to the Windows Registry, as follows:

Open the Windows Registry using the command regedit.

Tip:

It is recommended that you back up the registry before making any changes.

Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAT\Stingray\Debug\SETUP.